Why there is > 97% confidence that climate sensitivity to CO2 is not significantly different from zero

Looking at all of history, it is apparent that climate sensitivity [to CO2] can not be significantly different from zero.

If you understand the relation between mathematics and the physical world, you understand that, for a forcing to have an effect, it must exist for a period of time and the effect of the forcing is calculated by its duration. If the forcing varies, (or not) the effect is determined by the time-integral of the forcing (or the time-integral of a function thereof).

The CO2 level has been above about 150 ppmv for at least the entire Phanerozoic eon (the last 542 million or so years). If CO2 was a forcing, its effect on average global temperature (AGT) would be calculated according to its time-integral (or the time-integral of a function thereof) for about 542 million years. Because there is no possible way for that calculation to consistently result in the current average global temperature, CO2 cannot be a forcing.

Variations of this proof and identification of what does cause climate change (R^2 > 0.97 (greater than 97% statistical significance)) are at http://agwunveiled.blogspot.com

“If you understand the relation between mathematics and the physical world, you understand that, for a forcing to have an effect, it must exist for a period of time and the effect of the forcing is calculated by its duration. If the forcing varies, (or not) the effect is determined by the time-integral of the forcing (or the time-integral of a function thereof).”

Absolutely, which as you (and others) have clearly demonstrated rules out CO2 as a forcing and shows the time-integral of solar activity IS the climate forcing consistent with available paleoclimate and instrumental data, (and modulated by ocean oscillations, which in themselves are lagged effects of the solar forcing shown in the second graph below):